Mercurial > SDL_sound_CoreAudio
annotate decoders/mpglib/decode_i386.c @ 438:72ccb2916418
Initial add.
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Sun, 12 Jan 2003 21:11:15 +0000 |
| parents | 52b9f37998db |
| children |
| rev | line source |
|---|---|
| 261 | 1 /* |
| 2 * Mpeg Layer-1,2,3 audio decoder | |
| 3 * ------------------------------ | |
| 4 * copyright (c) 1995,1996,1997 by Michael Hipp, All rights reserved. | |
| 5 * See also 'README' | |
| 6 * | |
| 7 * slighlty optimized for machines without autoincrement/decrement. | |
| 8 * The performance is highly compiler dependend. Maybe | |
| 9 * the decode.c version for 'normal' processor may be faster | |
| 10 * even for Intel processors. | |
| 11 */ | |
| 12 | |
| 13 #include <stdlib.h> | |
| 14 #include <math.h> | |
| 15 #include <string.h> | |
| 16 | |
| 17 #include "mpg123_sdlsound.h" | |
| 18 #include "mpglib_sdlsound.h" | |
| 19 | |
| 20 /* old WRITE_SAMPLE */ | |
| 21 #define WRITE_SAMPLE(samples,sum,clip) \ | |
| 22 if( (sum) > 32767.0) { *(samples) = 0x7fff; (clip)++; } \ | |
| 23 else if( (sum) < -32768.0) { *(samples) = -0x8000; (clip)++; } \ | |
| 24 else { *(samples) = sum; } | |
| 25 | |
|
279
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
26 int synth_1to1_mono(real *bandPtr,unsigned char *samples, |
|
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
27 int *pnt, struct mpstr *mp) |
| 261 | 28 { |
| 29 short samples_tmp[64]; | |
| 30 short *tmp1 = samples_tmp; | |
| 31 int i,ret; | |
| 32 int pnt1 = 0; | |
| 33 | |
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279
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
34 ret = synth_1to1(bandPtr,0,(unsigned char *) samples_tmp,&pnt1,mp); |
| 261 | 35 samples += *pnt; |
| 36 | |
| 37 for(i=0;i<32;i++) { | |
| 38 *( (short *) samples) = *tmp1; | |
| 39 samples += 2; | |
| 40 tmp1 += 2; | |
| 41 } | |
| 42 *pnt += 64; | |
| 43 | |
| 44 return ret; | |
| 45 } | |
| 46 | |
| 47 | |
|
279
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
48 int synth_1to1(real *bandPtr,int channel,unsigned char *out, |
|
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
49 int *pnt, struct mpstr *mp) |
| 261 | 50 { |
| 51 static const int step = 2; | |
| 52 int bo; | |
| 53 short *samples = (short *) (out + *pnt); | |
| 54 | |
| 55 real *b0,(*buf)[0x110]; | |
| 56 int clip = 0; | |
| 57 int bo1; | |
| 58 | |
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279
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
59 bo = mp->synth_bo; |
| 261 | 60 |
| 61 if(!channel) { | |
| 62 bo--; | |
| 63 bo &= 0xf; | |
|
279
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
64 buf = mp->synth_buffs[0]; |
| 261 | 65 } |
| 66 else { | |
| 67 samples++; | |
|
279
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
68 buf = mp->synth_buffs[1]; |
| 261 | 69 } |
| 70 | |
| 71 if(bo & 0x1) { | |
| 72 b0 = buf[0]; | |
| 73 bo1 = bo; | |
| 74 dct64(buf[1]+((bo+1)&0xf),buf[0]+bo,bandPtr); | |
| 75 } | |
| 76 else { | |
| 77 b0 = buf[1]; | |
| 78 bo1 = bo+1; | |
| 79 dct64(buf[0]+bo,buf[1]+bo+1,bandPtr); | |
| 80 } | |
| 81 | |
|
279
52b9f37998db
Removed global state variable; should be thread safe now.
Ryan C. Gordon <icculus@icculus.org>
parents:
261
diff
changeset
|
82 mp->synth_bo = bo; |
| 261 | 83 |
| 84 { | |
| 85 register int j; | |
| 86 real *window = decwin + 16 - bo1; | |
| 87 | |
| 88 for (j=16;j;j--,b0+=0x10,window+=0x20,samples+=step) | |
| 89 { | |
| 90 real sum; | |
| 91 sum = window[0x0] * b0[0x0]; | |
| 92 sum -= window[0x1] * b0[0x1]; | |
| 93 sum += window[0x2] * b0[0x2]; | |
| 94 sum -= window[0x3] * b0[0x3]; | |
| 95 sum += window[0x4] * b0[0x4]; | |
| 96 sum -= window[0x5] * b0[0x5]; | |
| 97 sum += window[0x6] * b0[0x6]; | |
| 98 sum -= window[0x7] * b0[0x7]; | |
| 99 sum += window[0x8] * b0[0x8]; | |
| 100 sum -= window[0x9] * b0[0x9]; | |
| 101 sum += window[0xA] * b0[0xA]; | |
| 102 sum -= window[0xB] * b0[0xB]; | |
| 103 sum += window[0xC] * b0[0xC]; | |
| 104 sum -= window[0xD] * b0[0xD]; | |
| 105 sum += window[0xE] * b0[0xE]; | |
| 106 sum -= window[0xF] * b0[0xF]; | |
| 107 | |
| 108 WRITE_SAMPLE(samples,sum,clip); | |
| 109 } | |
| 110 | |
| 111 { | |
| 112 real sum; | |
| 113 sum = window[0x0] * b0[0x0]; | |
| 114 sum += window[0x2] * b0[0x2]; | |
| 115 sum += window[0x4] * b0[0x4]; | |
| 116 sum += window[0x6] * b0[0x6]; | |
| 117 sum += window[0x8] * b0[0x8]; | |
| 118 sum += window[0xA] * b0[0xA]; | |
| 119 sum += window[0xC] * b0[0xC]; | |
| 120 sum += window[0xE] * b0[0xE]; | |
| 121 WRITE_SAMPLE(samples,sum,clip); | |
| 122 b0-=0x10,window-=0x20,samples+=step; | |
| 123 } | |
| 124 window += bo1<<1; | |
| 125 | |
| 126 for (j=15;j;j--,b0-=0x10,window-=0x20,samples+=step) | |
| 127 { | |
| 128 real sum; | |
| 129 sum = -window[-0x1] * b0[0x0]; | |
| 130 sum -= window[-0x2] * b0[0x1]; | |
| 131 sum -= window[-0x3] * b0[0x2]; | |
| 132 sum -= window[-0x4] * b0[0x3]; | |
| 133 sum -= window[-0x5] * b0[0x4]; | |
| 134 sum -= window[-0x6] * b0[0x5]; | |
| 135 sum -= window[-0x7] * b0[0x6]; | |
| 136 sum -= window[-0x8] * b0[0x7]; | |
| 137 sum -= window[-0x9] * b0[0x8]; | |
| 138 sum -= window[-0xA] * b0[0x9]; | |
| 139 sum -= window[-0xB] * b0[0xA]; | |
| 140 sum -= window[-0xC] * b0[0xB]; | |
| 141 sum -= window[-0xD] * b0[0xC]; | |
| 142 sum -= window[-0xE] * b0[0xD]; | |
| 143 sum -= window[-0xF] * b0[0xE]; | |
| 144 sum -= window[-0x0] * b0[0xF]; | |
| 145 | |
| 146 WRITE_SAMPLE(samples,sum,clip); | |
| 147 } | |
| 148 } | |
| 149 *pnt += 128; | |
| 150 | |
| 151 return clip; | |
| 152 } | |
| 153 |